Heavy forms for vertical wall concrete castings in the past have generally been built with a combination of wood and steel or in some cases, where large amounts of repeat usage can be expected, on all steel form. In either case, the forms are most generally backed up vertically or in some cases horizontally with two heavier steel channels or wales, spaced on between 2 to 5 foot centers. As the channels are placed on the back of the form, they are spaced about 1-1/2to 2 inches apart to permit a heavy steel bolt or bolt-type of form tie to pass through the one form, through the zone that will become the concrete wall, and into and through the opposite form. In first constructing a heavy duty form, a plywood or steel facing is prepared that will be the confronting surface against the concrete. If plywood is used, and in most cases such plywood is 3/4 of an inch thick, it is generally backed up or reinforced with fir 4 .times. 4's or 4 .times. 6's on 12 inch centers. If a steel form face is used, in most cases 3/16 inch thick, it is most generally backed up with steel angles about 3 inches by 3 inches or light 3 or 4 inch steel channels, also on about 12 inch centers. The heavy steel stiff back channels or wales are then secured in place as before mentioned on two, three, four or five foot centers, depending on the tie spacing that is desired. The rate at which the concrete is to be placed and the height of the wall also helps to govern the tie spacing. As previously stated, the channels are spaced about 11/2 to 2 inches apart to permit a heavy steel bolt or bolt-type of form tie to pass between the forms from one side through the concrete zone and then through the opposite form on the other side.
In the past the bolt or tie has been designed with a standard thread or a coarse Acme thread, and secured in place with a large thick plate washer resting against the back of the two spaced steel channels or wales on the backside of each of the wall forms. Then, a nut is run down over the threads on each end of the tie to achieve the proper spacing for the wall thickness desired. With this type of form construction, there has never been a satisfactory provision for properly spacing and spreading the forms internally. Most of the ties used in the past in heavy concrete forming have been of the bolt design with a removable nut on each end. Because of the inability to strut the form panels apart, certain types of wall forming can create a problem in proper spacing. One good example is that of a battered wall where one of the forms is standing vertically, but the other form is tilted. Consider, for example, a wall that at the bottom is 30 inches in width and at the top of a 20 foot wall is only 12 inches in width. With this type of wall and a heavy form that will weigh often in excess of 10 pounds per square foot, there is a definite problem of the tilted form tending to fall against the face of the vertical wall form. Ties with a spreader or for a spacer have been used to hold both forms in the proper position. However, the spreaders or spacers may need to be sacrificed or, if removed, require plugging. Still a further problem encountered in this type of tie is that the installer can tighten the nut on one tie tighter than that on another, and then further down the wall, be looser than another, causing the wall to be wavy and for some of the ties to be overloaded and some ties not carrying any or very little load. This can also be dangerous and contribute to or cause a wall failure which in the industry is known as a "break out".
The present invention solves the problems indicated above and provides a tie and a form lock that can be used with any type of conventional gang form presently being marketed or built by the contractor, or for a form design utilizing the basic concept of a facing material or either wood or steel against the concrete. This in turn is backed up with either wood or steel preferably running horizontally. Then vertically, this assembly is backed with heavy steel channels on two to four or five foot centers running from the bottom to the top of the form and acting as a strong back and the main member to which the locks of the present invention are attached to receive the pressure of the wet concrete. These channels or wales are usually applied in pairs and spaced about two inches apart. It is to these vertical spaced apart channel members or wales that the locks of the present invention are applied on a prescribed spacing not to exceed about five feet by five feet.